PHPS Hash

What is PHPS?

The **PHPS** hash format, derived from the PHP password hashing scheme introduced in PHP 5.3.7 (released in 2010), is a cryptographic hash structure designed to store user passwords securely within relational databases. Structurally, PHPS hashes are composed of a **salted, iterative HMAC-based** (typically SHA-256 or SHA-512) hash of the password, encoded in a base64url format. The format begins with a prefix (`$P$` for SHA-256 or `$H$` for SHA-512), followed by a cost parameter (a numeric iteration count), a salt (a 22-character hexadecimal string), and the final hash value. This design was intended to mitigate brute-force attacks by incorporating a configurable iteration count (cost factor) and a per-password salt, though its security was later deemed insufficient for modern threats. PHPS was primarily used in PHP applications to replace weaker hashing methods like MD5 or plain SHA-1, offering a balance between performance and security at the time of its adoption.

The PHPS format is vulnerable to cracking due to several architectural flaws exacerbated by advancements in computational power. The **lack of a strong salt implementation** in early versions (e.g., fixed-length salts) allows for precomputation attacks like rainbow tables, though later iterations improved this. More critically, the **iteration count (cost factor) is often too low** (e.g., 1000–2000 iterations) to resist GPU/ASIC-based brute-force attacks, which can now evaluate billions of hashes per second. Additionally, the **use of HMAC-SHA-256/SHA-512 without key stretching optimizations** (e.g., Argon2 or bcrypt’s adaptive hashing) makes it susceptible to **optimized GPU cracking tools** like Hashcat, which leverage parallel processing to exploit weak iteration counts. Finally, the **base64url encoding introduces no cryptographic security**, and the format’s reliance on legacy PHP functions (e.g., `password_hash()` with `PASSWORD_DEFAULT`) can default to insecure parameters if misconfigured, further compromising its resilience against modern attack vectors.

Identifying PHPS Hashes

Identifying a hash blindly is often difficult because multiple algorithms can output strings of the exact same length. For example, a standard 32-character hexadecimal string could be MD5, NTLM, MD4, or LM. To definitively identify PHPS, security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack PHPS

If you need to recover the plaintext password for a PHPS hash during a penetration test or forensics investigation, you must supply the correct module ID to your cracking software. Use the exact commands provided at the top of this page to target the hash successfully.